The synthesis and characterization of the pendant-armed ligand N,N′-bis(2′-pyridylmethyl)-1,7-dithia-4,11-diazacyclotetradecane (L₄) and crystal structures of L₄ and the copper(II) complex [Cu(L₄)](ClO₄)₂ — Crystal structure of the nickel(II) complex of N-(2′-pyridylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L₂), [Ni(L₂)(CH₃CN)](ClO₄)₂·CH₃CN

Abstract

The synthesis and characterization of the mixed donor ligand N,N′-bis(2′-pyridylmethyl)-1,7-dithia-4,11-diazacyclotetradecane (L4) containing two pendant pyridine arms is described. The macrocycle formation involves reaction of N-tosylbis(2-bromoethyl)amine with N-tosylbis(3-mercaptopropyl)amine at high dilution followed by detosylation at the nitrogen atoms using LiAlH4 in view of the presence of the thioether groups. An X-ray study of the ligand shows the sulphur atoms lie exo to the macrocyclic ring. The nickel(II) and copper(II) complexes of L4 have been characterized and the X-ray structure of the Cu(II) ion exhibits a five-coordinate copper ion despite the presence of six available donor atoms. In the case of ligand N-(2-pyridylmethyl)-1,4,7-trithia-11-azacyclotetradecane (L2), with a single pendant N donor, the Ni(II) complex is distorted octahedral with a molecule of acetonitrile in the sixth site. Details of UV–vis, ESR spectra, and electrochemical studies on the complexes are presented.Key words: synthesis, pendant-armed, mixed donor S,N macrocycles, copper, nickel.

Synthesis and Antibacterial Evaluation of Some Novel Imidazole and Benzimidazole Sulfonamides

“…Three bis-benzimidazole sulfonamides and three bis-imidazole sulfonamides compounds were obtained by treating imidazole (or benzimidazole) with tris-(4-substituted benzensulfonate)- diethanolamine under basic conditions to form the corresponding bis-imidazole (or bis-benzimidazole) sulfonamides. The reaction of tris-(4-substituted benzensulfonate) with either imidazole or benzimidazole has produced symmetrical products and it is in agreement with literature [28] to synthesize tris-(4-substituted benzensulfonate)-diethanolamine. In the current study, this intermediate was applied as a reagent to synthesize symmetric bis-imidazole (or bis-benzimidazole) sulfonamide compounds.…”

“…These compounds were prepared according to the modified procedure described in [28]. Diethanolamine (5.5 g, 0.0524 mol) was dissolved in distilled dichloromethane (100 mL).…”

Electrochemical CO2 Reduction — The Effect of Chalcogenide Exchange in Ni-Isocyclam Complexes

“… a Conditions: (a) H 2 O, reflux, 24 h; (b) DCM, NEt 3 , TsCl, 0 °C, 3 h → rt, 12 h; (c) (1) NaOH, H 2 O, (2) TsCl, DCM, rt, 12 h; (d) (1) PPh 3 , THF/H 2 O, reflux, 48 h, (2) NaOH, 2-chloroethylamine, reflux, 12 h; (e) (1) NaOH, H 2 O, (2) TsCl, DCM, rt, 12 h; (f) (1) TsCl, DCM, 0 °C, (2) NEt 3 , 0 °C, 1 h; (g) [E = Se] EtOH, reflux, 2 h; (h) [E = Te] EtOH/H 2 O, reflux, 2 h; (i) [E = Se] EtOH, reflux, 12 h; (j) [E = Te] EtOH/H 2 O, reflux, 12 h; (k) Cs 2 CO 3 , DMF, rt, 3 days; (l) [E = NTs] concentrated H 2 SO 4 , 100 °C, 5 days; (m) [E = O, S] phenol, 33% HBr in HOAc, reflux, 72 h; (n) [E = Se] (1) Na-naphthalenide, DME, −45 °C, (2) NaHCO 3 , −45 °C → rt, 12 h. …”

“…Dipropanolamine ( 2 ) was synthesized by condensation of 2 equiv of 3-amino-1-propanol with 1 equiv of 3-chloro-1-propanol and obtained as a colorless oil in 53% yield . Tosylation of 2 with 3 equiv of tosyl chloride subsequently afforded 1 as a colorless solid in 83% yield . In parallel, reaction of diethylenetriamine with 3 equiv of tosyl chloride afforded 3-N as a colorless solid in 79% yield .…”

Synthesis of a Spirocyclic Oxetane-Fused Benzimidazole

“…Diethyl malonate (0.500 g, 3.1 mmol) and NaH (0.165 g, 6.9 mmol) in DMF (50 mL) were heated at 80 °C for 30 min. N,N-bis(2-bromoethyl)-4-methyl-1-sulfonamide [14] (1.320 g, 3.4 mmol) was added and heating at 80 °C continued for 12 h. The cooled mixture was evaporated, EtOAc (50 mL) added, and washed with aqueous LiCl (5%) solution (3 × 50 mL). The organic extracts were dried (Na2SO4) and evaporated to dryness, and the residue purified by column chromatography using gradient elution of petroleum ether/EtOAc to yield the title compound (0.987 g, 83%) as a white solid; Rf 0.32 (1:4 EtOAc/Pet); mp 90-92 °C; νmax (neat, cm (5).…”